Multiple circuit breaker assembly



Aug. 3, 1965 B. A. PITEO, JR 3,198,398

MULTIPLE CIRCUIT BREAKER ASSEMBLY Filed June '7, 1963 2 Sheets-Sheet 1 /NVENTOR. BENJA M/N A. P/TE 0,JR.

ATTORNEY.

1965 B. A. PlTEO, JR 3,198,898

MULTIPLE CIRCUIT BREAKER ASSEMBLY Filed June 7, 1963 2 Sheets-Sheet 2 /NVENTOR. BENJA M/N A. P/ T0,JR.,

ATTORNEY.

United States Patent 3,198,898 MULTIPLE CIRIJUIT BREAKER ASSEMBLY Beniamin A. Piteo, .ln, Forestville, Conn, assignor to General Electric (Zompany, a cerporation of New York Fiied June 7, 1963, Ser. No. 286,251 3 Claims. (Cl. 290- My invention relates to multiple circuit breakers of the manually operable type, and more particularly to an assembly of two or more individual circuit breakers in a common casing provided with an improved handle tie for simultaneous or ganged operation.

Electric circuit breakers of the manually operable, current responsively tripped type adapted for use in the control of branch lighting and power circuits of relatively small capacity have heretofore been assembled in pairs in a common casing. Such circuit breakers are typically complete individual devices of the overcenter or snapaction type having separate current responsive trip elements and provided with separate manually operable handles protruding from the casing. Dual circuit breakers of this type have been assembled in a common casing in both side-by-side and end-to-end relation, and handle couplings have been provided for simultaneous operation. For indication of automatic trip operation or for automatic reset of the breakers, or both, it is usually necessary to provide within each circuit breaker means for biasing the handle toward its open circuit position.

It is an object of my invention to provide an improved end-to-end or tandem assembly of such small manually operable circuit breakers having an external handle tie providing common reset and trip indicating bias.

It is another object of my invention to provide an enclosed handle tie for dual circuit breakers disposed in end-to-end relation so constructed and arranged that a minimum of movable operating mechanism is exposed thereby to provide a maximum of electrical and mechanical safety.

In carrying out my invention in one preferred embodiment, I provide a narrow elongated casing of suitable molded plastic insulating material arranged to have mounted therein in end-to-end relation a pair of substantially identical circuit breakers includin operating mechanisms of the overcenter snap-action type, individual overcurrent responsive tripping elements and individual operating handles of the pivoted or rotary type protruding from the casing and angularly movable in spaced apart substantially co-planar relation. The mechanisms are so disposed in the casing that the handles move in like directions to effect closure, opening and resetting, respectively, of the individual circuit breaker mechanisms. Exteriorly of the main casing but preferably enclosed within an elongated shroud or cover, I provide a rectilinearly movable connecting link or rod coupled at opposite ends to the anguarly movable external handle portions. Interposed between suitable abutments on the handle tie and on the casing or shroud, I provide a biasing spring disposed to move the rotary handles toward their open circuit positions. Preferably the spring is helical in form and surrounds the tie rod.

My invention will be more fully understood and its various objects and advantages further appreciated by referring now to the following detailed specifications taken in conjunction with the accompanying drawings in which:

FIGURE 1 is a perspective view of a complete circuit breaker assembly with the main casing integral and only a portion of the handle shroud broken away to illustrate the tie connection;

FIGURE 2 is a side elevational view of a dual circuit 3,198,898 Patented Aug. 3, 1965 breaker assembly embodying my invention, the casing being partially broken away to expose exemplary circuit breaker mechanisms in its open circuit position and to illustrate the handle tie connection, and

FIGURE 3 is a side elevational view of the circuit breaker assembly shown at FIGURE 2 showing the circuit breakers in their contact closing positions.

Referring now to the drawings and particularly to FIGURE 2, I have illustrated my invention as applied to a pair of individual electric circuit breakers mounted in end-to-end or tandem relation in a common narrow elongated casing 10 formed of suitable molded plastic insulating material and having a main casing portion enclosing the circuit breaker mechanisms and an integral handle shroud portion 10b formed on the upper edge surface thereof. The individual circuit breaker mechanisms enclosed in the main casing portion 10a are provided with individual rotary operating handles 34 including manually engageable handle portions 11 and 12 which extend beyond the upper edge of the main casing portion 10a adjacent opposite ends of the handle shroud 10b.

The handle portions 11 and 12 are angularly movable in like directions to open and to close their associated circuit breakers and are connected together by a rigid elongated tie bar or link 13 which extends longitudinally through the shroud portion 10b of the casing and is pivotally connected at opposite ends to the external portions 11 and 12. Within the shroud portion 10b of the circuit breaker casing there is provided a fixed abutment 14 formed as an integral part of the casing, and the abutment 14 is slotted or apertured to permit sliding movement of the tie rod 13 therethrough. A helical com pression spring 15 is mounted coaxially upon the tie rod 13 and interposed between the fixed abutment 14 and a spring seat 16 fixed to the rod 13.

The circuit breaker assembly shown in the drawing is of the plug-in type, and for this purpose the main casing portion 10a is shown provided with a pair of spaced apart upright slots 17 and 18 adjacent its lower edge for plug-in connection to a pair of parallel electric bus bars B as will be more evident from examination of FIGURES 2 and 3.

While the individual circuit breaker mechanisms disposed in end-to-end relation in the common casing portion 10a may be of any desired overcenter or other snapacting type, I have illustrated at FIGURES 2 and 3 a preferred manually operable, current-responsively tripped snap-acting mechanism of the releasable cam and wedge tye. The illustrated manually operable mechanism is fully described and claimed in a co-pending patent application S.N. 242,424 filed on December 5, 1962, by David B. Powell, now Patent No. 3,171,928 issued March 2, 1965, and assigned to the same assignee as instant application, and the thermal responsive overcurrent tripping element illustrated is described and claimed in co-pending application S.N. 284,923 filed on January 2, 1963 by Klein and Powell, now Patent No. 3,171,930 issued March 2, 1965, and assigned to the same assignee as the instant application.

As illustrated at FIGURES 2 and 3, the dual circuit breaker comprises two identical operating mechanisms (only one of which is shown) adapted, respectively, to make and break separate electric circuits. The circuits through each breaker extend from one of a pair of line terminal clips 17a and 13a adjacent the casing 10a. Since the two individual breaker mechanisms in the common casing 10a are identical and arranged so that the protruding handle portions 11 and 12 move in like directions for circuit opening and circuit closing movement, a stationary contact 21 of one breaker is mounted upon the load terminal member 19, and a stationary contact 21a of the other breaker is mounted upon the line terminal clip 18a. In all other respects the circuit breaker mechanisms are of identical structure and each comprises, as shown at FIGURES 2 and 3, a movable contact arm 22 carrying a movable contact 22a and loosely pivotally mounted upon a pin 23 fixed in the main casing a. The contact arm 22 is biased to open circuit position by a compression spring 24 interposed between the arm 22 and a spring seat in the main casing 10a.

The operating mechanism for manually and automatically moving the circuit breaker contact arm 22 between open circuit and closed circuit positions comprises a releasable tripping member 25 shown as flat plate of insulating material loosely pivotally mounted upon a pivot pin 26 and having at its side adjacent contact arm 22 a cam surface 2'7. The cam surface 27 is formed in two parts providing therebetween an apex point 27a with which a cam follower cooperates with an overcenter wedging and locking action to be more fully described hereinafter. The releasable tripping member 25 is normally restrained against tripping movement by a thermostatic latch member 28 having a latching detent 28a normally in latching engagement with the tripping member 25. The thermal responsive member 28 is formed as a generally U-shaped strip of deformable bimetallic material loosely mounted at its bright upon a casing abutment 29 and arranged when excessively heated to spred apart its side arms. As described in the foregoing co-pending patent application S.N. 248,923, when the bimetallic strip 28 spreads its side arms one arm first engages an abutment 28b on the tripping member 25 to act as a prop, and thereafter further spreading of the arms disengages the latching detent 28a.

For manual opening and closing operation of the circuit breaker, I provide an overcenter wedging mechanism cooperable with the cam surface 27 on the releasable member 25 and with the movable contact arm 22. For this purpose the lateral edge of the contact arm 22 adjacent the normally fixed cam surface 27 constitutes a cooperating cam surface 30 of essentially linear configuration and is disposed to converge toward the cam surface 27 in the open circuit position of the parts illustrated at FIGURE 2. For manual closing and opening operation there is provided a movable wedging roller 31 mounted upon a pivot pin 32 at the free end of a swinging link 33. The link 33 is pivotally mounted eccentrically upon the rotary handle member 34 carried by the fixed pivot 26. The rotary handle member 34 is preferably formed integrally with the extending manually engageable portion 11 and is provided internally of the casing 10a with a radial arm upon which the swinging link 33 is pivotally mounted by means of a pin 35. The upper body portion of the rotary handle member 34 is provided with an arcuate rim 36, one end of which serves as an abutment or shoulder to engage the releasable tripping member 25 when released and return it to its latched position.

To illustrate the manual opening and closing operation of my improved multiple circuit breaker mechanism, let it be assumed that both circuit breakers are in their open circuit positions with the releasable tripping members 25 latched by the thermal detents 28a and the wed ing rollers 31 withdrawn upwardly with respect to the converging cam surfaces 27 and 30, as shown at FIG- URE 2. In this position the rotary handle members 34 are free to rotate to their open circuit positions (clockwise as shown in the drawing) and are held in these positions by the biasing spring 15 which encircles the handle tie rod 13. To close the circuit breakers manually the handle portion 12 is engaged and moved angularly counterclockwise thereby to slide the tie rod 13 to the left against the bias of the spring 15. By this movement both rotary handle members 34 are simultaneously moved counterclockwise and the swinging links. 33 are moved downward to interpose the rollers 31 in wedging relation between the cam surfaces 27 and 30. In thus moving to the circuit-closing position shown at FIGURE 3, each wedging roller 31 moves over its stationary cam surface 27 and forces the associated pivoted contact arm 22 to closed circuit position against the bias of the spring 24. In its final movement along the cam surface 27, each roller 31 moves over the apex point 27a and is locked in closing position on the opposite side of the apex by pressure of the contact arm spring 24. To permit this overcenter movement the contact arm 22 is slotted at point of connection with the pivot pin 23. It will f course, be understood that the opening bias of the handle spring 15 is lHSlliTlClCIlt to overcome the overcenter locking action of the two wedging rollers 31. It will be evident also that manual opening operation is the reverse of the wedging action just described, the handle portions 11 and 12 being moved clockwise to their open circuit positions as soon as the rollers 31 are moved upwardly be yond the apex points 27a.

The action of the common biasing spring 15 within the handle shroud 10b in providing both trip indicators and automatic reset of the illustrated circuit breakers will be evident by examining now the automatic tripping operation of these breakers. Referring to FIGURE 3 in which the illustrated circuit breaker mechanism is shown in its closed circuit position, it will be evident that the releasable tripping member 25 is biased for counterclockwise movement by the contact arm spring 24, force being applied to the tripping member 25 through the contact arm 22 and the wedging roller 31. Accord ingly, whenever the restraining force on the releasing tripping member 25 is withdrawn by thermal expansion and unlatching of the bimetallic trip member 28, the releasable member 25 moves counterclockwise suiliciently to release its locking action upon the wedging roller 31. When the wedging rollers 31 are released, the rotary handle members 34 are free to move clockwise to their open circuit positions under the influence of the common biasing spring 15. In so moving, the wedging rollers 31 are withdrawn upwardly to release the contact arms 22 for circuit-opening movement and the rotary handle members 34 engage the releasable tripping members 25 to return these members to their normal latching positions in readiness for relatching as soon as the bimetallic members 28 cool sufiiciently to return to normal position.

In will now be evident that I have provided an improved dual circuit breaker assembly in which, as a result of tandem coplanar relation and similar operating orientation of the manual handles, the handles may be connected for ganged operation by a simple rectilinearly movable link and the external linkage so shrouded or enclosed that only a single one of the operating handles protrudes from the shroud in any breaker position. Moreover in assemblies where automatic reset and trip indication is desired, space within the indivdual circuit breakers is conserved by providing within the handle shroud a common handle basing spring external of the main circuit breaker casing.

While I have described only a preferred embodiment of my invention by way of illustration, many modifications will occur to those skilled in the art, and I therefore wish to have it understood that I intend in the appended claims to cover all such modifications as fall with in the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A multiple circuit breaker assembly comprising a pair of snap-action electric circuit breakers mounted in end-to-end relation in a common casing and having individual rotary handles mounted in spaced apart substantially coplanar relation, said handles having external manually engageable portions projecting outside said casing movable in like direction to eifect simultaneously circuit opening and circuit closing movement of their respective circuit breakers, a rectilinearly movable coupling rod connecting said external manually engageable portions together for simultaneous movement, and a single handle biasing spring of helical configuration surrounding said rod and having two ends, one of its ends engaging said rod, and its other end engaging said casing to bias both said handles to open circuit positions.

2. A multiple circuit breaker assembly comprising a pair of individual snap-action electric circuit breakers mounted in end-to-end relation in a common elongated casing and having individual rotary handles mounted in spaced apart substantially co-planar relation, said handles including external manually engageable portions angularly movable in like directions to effect circuit opening and circuit closing movement of their respective circuit breakers, a rectilinearly movable coupling rod connecting said manually engageable portions exteriorly of said casing, an elongated enclosing housing covering said coupling rod for substantially its entire length and exposing only one of said manually engageable portions in each limiting position of said manually engageable portions, and a helical spring encircling said rod within said housing and having two ends, one of its ends engaging said rod, and its other end engaging said casing to bias said handle levers to their circuit opening positions.

3. A multiple circuit breaker assembly comprising an insulating casing, a pair of circuit breaker operating mechanisms mounted in said insulating casing in an endto-end relation, each of said mechanisms comprising a pivotally supported contact arm having a first cam surface and a pivotally mounted releasable trip member having a second cam surface, a biasing spring biasing said contact arm toward open-circuit position, a rotary handle mounted in said casing and having a link pivotally connected thereto, said link carrying a wedging member acting between said first and second cam surfaces to move said contact arm to closed circuit position against the bias of said biasing spring, said handle having an external manually engageable portion projecting outside said casing, a rectilinearly movable coupling rod connecting said external manually engageable portions of said handles of each of said mechanisms together for simultaneous movement, and a single biasing spring surrounding said rod and having its ends interposed between said rod and said casing to bias both of said handles to open circuit position, said operating handles each having a portion engageable with said releasable trip member of the corresponding mechanism, whereby said single biasing spring acts through said operating handles to reset both of said releasable members.

References Cited by the Examiner UNITED STATES PATENTS 2,099,585 11/37 Von Hoorn 200-48 2,524,215 10/50 Wegehoft 200172 2,841,666 7/58 Anderson 200-50 KATHLEEN H. CLAFFY, Primary Examiner. BERNARD A. GILHEANY, Examiner. 

1. A MULTIPLE CIRCUIT BREAKER ASSEMBLY COMPRISING A PAIR OF SNAP-ACTION ELECTRIC CIRCUIT BREAKERS MOUNTED IN END-TO-END RELATION IN A COMMON CASING AND HAVING INDIVIDUAL ROTARY HANDLES MOUNTED IN SPACED APART SUBSTANTIALLY COPLANAR RELATION, SAID HANDLES HAVING EXTERNAL MANUALLY ENGAGEABLE PORTIONS PROJECTING OUTSIDE SAID CASING MOVABLE IN LIKE DIRECTION TO EFFECT SIMULTANEOUSLY CIRCUIT OPENING AND CIRCUIT CLOSING MOVEMENT OF THEIR RESPECTIVE CIRCUIT BREAKERS, A RECTILINEARLY MOVABLE COUPLING ROD CONNECTING SAID EXTERNAL MANUALLY ENGAGEABLE PORTIONS TOGETHER FOR SIMULTANEOUS MOVEMENT, AND A SINGLE HANDLE BIASING SPRING OF HELICAL CONFIGURATION SURROUNDING SAID ROD AND HAVING TWO ENDS, ONE OF ITS ENDS ENGAGING SAID ROD, AND ITS OTHER END ENGAGING SAID CASING TO BIAS BOTH SAID HANDLES TO OPEN CIRCUIT POSITIONS. 